Question

plz tell how to do it and also how to use constraint relation.

Answer 1

Answer:

David Cohen, Peter Jeavons, in Foundations of Artificial Intelligence, 2006

Example 8.13.

The class of constraints known as linear Horn constraints was introduced in [55, 62] and shown to be tractable.

The constraint relation of a linear Horn constraint is a relation over an infinite ordered set which is specified by a disjunction of an arbitrary finite number of linear disequalities and at most one weak linear inequality. The following are examples of linear Horn constraints:

Linear Horn constraints are an important class of linear constraints for expressing problems in temporal reasoning [55]. In particular, the class of linear Horn constraints properly includes the point algebra of [92], the (quantitative) temporal constraints of [60, 61] and the ORD-Horn constraints of [77].

Advanced Consistency Methods

Rina Dechter, in Constraint Processing, 2003

8.3.2 Constraint Tightness

The notion of domain tightness can be extended from unary scope relations (domains) to arbitrary relations having any scope size, allowing a similar relationship with bounded local consistency